Masters Theses


"Initial testing and a preliminary calibration were conducted in the UMR supersonic variable Mach number axisymmetric blowdown wind tunnel facility. During initial operations problems were encountered with control valve seat failure, control valve response and stability, and automatic operation. After having brittle fracture failures with seats made of nylon, Teflon and Telfon-copper composite, a copper seat was found to perform satisfactorily with minimal valve leakage. Control valve response and stability were greatly influenced by the setting of the needle valve located between the total pressure probe and the controller. The needle valve setting was observed to depend upon the stagnation pressure, the supply pressure, and the rate at which the valve was stroked. The result of each of the various methods of automatic operation tried was a pressure overshoot, bursting bypass diaphragms. Through manual operation excellent repeatability of stagnation pressure was obtained. The tunnel calibration vats performed at a stagnation pressure of 180 psig. By means of schlieren flow visualization the free jet was found to be completely expanded at this pressure. From cone-shock angle measurements the test section Mach number was approximately 2.8. A more discreetly defined nozzle contour and improved machining and polishing techniques are needed to rid the flow field of Mach waves emanating from the nozzle. An estimate of the run time by an empirical quasi-steady isentropic analysis was found to be in good agreement with the experimentally determined value"--Abstract, page ii.


Selberg, B. P.

Committee Member(s)

Howell, Ronald H. (Ronald Hunter), 1935-
Ho, C. Y. (Chung You), 1933-1988


Mechanical and Aerospace Engineering

Degree Name

M.S. in Aerospace Engineering


University of Missouri--Rolla

Publication Date



viii, 67 pages

Note about bibliography

Includes bibliographical references (pages 114-115).


© 1970 James Riley Murphy, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Supersonic wind tunnels -- Calibration
Valves -- Automatic control
Wind tunnels -- Flow visualization

Thesis Number

T 2472

Print OCLC #


Electronic OCLC #